Pressure Effect on Humidity Diffusion through Polyester/Glass Fiber Composite in Sea Water

Abstract

The hygrothermal behavior of the polyester/glass fiber composite is studied under the effect of the pressure in sea water. Fillers additives Aluminum Silicate Pigments are inserted to the composite material. Humidity absorption is made through one lateral side, under different temperature. The humidity concentration is higher on the surface and it continuously decreases toward the core of the material. At high temperature, the humidity absorption curve falls. It is caused by the coalescence of cracks propagating through the composite material, which are created by the stress concentration at a point of the free volume existing in the material. The rise of the percentage of the fillers additives and the pressure induces an augmentation of the diffusion coefficient and the amount of absorbed humidity. The finite element method is utilized to present a numerical model of the humidity absorption process. The comparison between numerical and experimental results confirms that the hygrithermal behavior of the polyester/ glass fiber composite could be numericallypredicted.